/*  
    日志器模块  
    1.抽象日志器基类
    2.派生出不同子类(同步日志器类和异步日志器类)
 */
#ifndef __M_LOGGER_
#define __M_LOGGER_
#ifndef _GUN_SOURCE
#define _GUN_SOURCE
#endif

#include "util.hpp"
#include "level.hpp"
#include "format.hpp"
#include "looper.hpp"
#include "sink.hpp"
#include <thread>
#include <atomic>
#include <mutex>
#include <cstdarg>
#include <unordered_map>

namespace log{
    class Logger{
        public:
            using ptr = std::shared_ptr<Logger>;
            Logger(const std::string& logger_name,
                LogLevel::value level,
                Formatter::ptr &formatter,
                std::vector<logSink::ptr>& sinks)
                :_logger_name(logger_name)
                ,_limit_level(level)
                ,_formatter(formatter)
                ,_sinks(sinks.begin(), sinks.end())
                {}
            const std::string& name(){
                return _logger_name;
            }
            //完成构造日志消息对象过程并进行格式化，得到格式化后的日志消息字符串 -- 最后进行落地输出
            void debug(const std::string& file, size_t line, const std::string& fmt, ...){
                //通过传入的参数构造出一个日志消息对象，进行日志的格式化，最终落地
                //1.判断当前日志是否达到了日志输出等级
                if(LogLevel::value::DEBUG < _limit_level) { return; }
                //2.对fmt格式化字符串和不定参进行字符串组织，得到日志消息的字符串
                va_list ap;
                va_start(ap, fmt);
                char* res;
                int ret = vasprintf(&res, fmt.c_str(), ap);
                if(ret == -1){
                    std::cout << "vasprintf failed\n"; 
                    return;
                }
                va_end(ap);
                serialize(LogLevel::value::DEBUG, file, line, res);
                free(res);
            }
            void info(const std::string& file, size_t line, const std::string& fmt, ...){
                //1.判断当前日志是否达到了日志输出等级
                if(LogLevel::value::INFO < _limit_level) { return; }
                //2.对fmt格式化字符串和不定参进行字符串组织，得到日志消息的字符串
                va_list ap;
                va_start(ap, fmt);
                char* res;
                int ret = vasprintf(&res, fmt.c_str(), ap);
                if(ret == -1){
                    std::cout << "vasprintf failed\n"; 
                    return;
                }
                va_end(ap);
                serialize(LogLevel::value::INFO, file, line, res);
                free(res);
            }
            void warn(const std::string& file, size_t line, const std::string& fmt, ...){
                //1.判断当前日志是否达到了日志输出等级
                if(LogLevel::value::WARN < _limit_level) { return; }
                //2.对fmt格式化字符串和不定参进行字符串组织，得到日志消息的字符串
                va_list ap;
                va_start(ap, fmt);
                char* res;
                int ret = vasprintf(&res, fmt.c_str(), ap);
                if(ret == -1){
                    std::cout << "vasprintf failed\n"; 
                    return;
                }
                va_end(ap);
                serialize(LogLevel::value::WARN, file, line, res);
                free(res);
            }
            void error(const std::string& file, size_t line, const std::string& fmt, ...){
                //1.判断当前日志是否达到了日志输出等级
                if(LogLevel::value::ERROR < _limit_level) { return; }
                //2.对fmt格式化字符串和不定参进行字符串组织，得到日志消息的字符串
                va_list ap;
                va_start(ap, fmt);
                char* res;
                int ret = vasprintf(&res, fmt.c_str(), ap);
                if(ret == -1){
                    std::cout << "vasprintf failed\n"; 
                    return;
                }
                va_end(ap);
                serialize(LogLevel::value::ERROR, file, line, res);
                free(res);
            }
            void fatal(const std::string& file, size_t line, const std::string& fmt, ...){
                //1.判断当前日志是否达到了日志输出等级
                if(LogLevel::value::FATAL < _limit_level) { return; }
                //2.对fmt格式化字符串和不定参进行字符串组织，得到日志消息的字符串
                va_list ap;
                va_start(ap, fmt);
                char* res;
                int ret = vasprintf(&res, fmt.c_str(), ap);
                if(ret == -1){
                    std::cout << "vasprintf failed\n"; 
                    return;
                }
                va_end(ap);
                serialize(LogLevel::value::FATAL, file, line, res);
                free(res);
            }
        protected:
            void serialize(LogLevel::value level, const std::string& file, size_t line, char* str){
                //3.构造LogMsg对象
                LogMsg msg(level, line, file, _logger_name, str);
                //4.通过格式化工具对LogMsg进行格式化，得到格式化后的日志字符串
                std::stringstream ss;
                _formatter->format(ss, msg);
                //5.进行日志落地
                Log(ss.str().c_str(), ss.str().size());
            }
            //抽象接口完成实际的落地输出 -- 不同的日志器有不同的实际落地方式
            virtual void Log(const char* data, size_t len) = 0;
        protected:
            std::mutex _mutex;
            std::string _logger_name;
            std::atomic<LogLevel::value> _limit_level;
            Formatter::ptr _formatter;
            std::vector<logSink::ptr> _sinks;

    };
    //同步日志器
    class SyncLogger : public Logger{
        public:
            SyncLogger(const std::string& logger_name,
                LogLevel::value level,
                Formatter::ptr &formatter,
                std::vector<logSink::ptr>& sinks)
                :Logger(logger_name, level, formatter, sinks)
            {}
        protected:
            //同步日志器，是将日志直接通过落地模块句柄进行日志落地
            void Log(const char* data, size_t len){
                std::unique_lock<std::mutex> lock(_mutex);
                if(_sinks.empty()) return;
                for(auto& sink : _sinks){
                    sink->Log(data, len);
                }
            }
    };
    //异步日志器
    class AsyncLogger : public Logger{
        public:
            AsyncLogger(const std::string& logger_name,
                LogLevel::value level,
                Formatter::ptr &formatter,
                std::vector<logSink::ptr>& sinks,
                AsyncType _lopper_type)
                :Logger(logger_name, level, formatter, sinks)
                ,_lopper(std::make_shared<AsyncLooper>(std::bind(&AsyncLogger::reaLog, this, std::placeholders::_1), _lopper_type))
                {}
            //将数据写入缓冲区
            void Log(const char* data, size_t len){
                _lopper->push(data, len);
            }
            //实际落地函数，将缓冲区中的数据进行实际落地
            void reaLog(Buffer& buffer){
                if(_sinks.empty()) return;
                for(auto& sink : _sinks){
                    sink->Log(buffer.begin(), buffer.readAblesSize());
                }
            }
        private:
            AsyncLooper::ptr _lopper;
    };

    enum class LoggerType{
        LOGGER_SYNC,
        LOGGER_ASYNC
    };
    //使用建造者模式来建造日志器，而不要让用户直接去构造日志器，简化用户的复杂度
    //1.抽象一个日志器建造者类（完成日志器对象所需零部件的构建 & 日志器的构建）
    //  1.设置日志器类型
    //  2.将不同类型日志器的创建放在同一个日志器建造者类中完成
    class LoggerBuilder{
        public:
            LoggerBuilder()
            :_logger_type(LoggerType::LOGGER_SYNC)
            ,_limit_level(LogLevel::value::DEBUG)
            ,_lopper_type(AsyncType::ASYNC_SAVE)
            {}
            void buildLoggerType(LoggerType type){
                _logger_type = type;
            }
            void buildLoggerName(const std::string& name){
                _logger_name = name;
            }
            void buildLoggerLevel(LogLevel::value level){
                _limit_level = level;
            }
            void buildFormatter(const std::string& pattern){
                _formatter = std::make_shared<Formatter>(pattern);
            }
            void bulidEnableUnSafeAsync() {
                _lopper_type = AsyncType::ASYNC_UNSAVE;
            }
            template<typename SinkType, typename ...Args>
            void buildSink(Args && ...args){
                logSink::ptr psink = SinkFactory::create<SinkType>(std::forward<Args>(args)...);
                _sinks.push_back(psink);
            }
            virtual Logger::ptr build() = 0;
        protected:
            AsyncType _lopper_type;
            LoggerType _logger_type;
            std::string _logger_name;
            LogLevel::value _limit_level;
            Formatter::ptr _formatter;
            std::vector<logSink::ptr> _sinks;
    };
    //2.派生出具体的建造者类 -- 局部日志器建造者 & 全局日志器建造者
    class LocalLoggerBuilder : public LoggerBuilder{
        public:
            Logger::ptr build() override{
                assert(!_logger_name.empty());//日志器名字是必须要有的
                if(_formatter.get() == nullptr){
                    _formatter = std::make_shared<Formatter>();
                }
                if(_sinks.empty()){
                    buildSink<StdoutSink>();
                }
                if(_logger_type == LoggerType::LOGGER_ASYNC){
                    return std::make_shared<AsyncLogger>(_logger_name, _limit_level, _formatter, _sinks, _lopper_type);
                }
                return std::make_shared<SyncLogger>(_logger_name, _limit_level, _formatter, _sinks);
            }
    };

    class LoggerManager{
        public:
            static LoggerManager& getInstance(){
                //在c++11之后，针对静态局部变量，编译器在编译的层面实现了线程安全
                //当静态局部变量没有构造完成之前，其他的线程进入会阻塞
                static LoggerManager eton;
                return eton;
            }
            void addLogger(Logger::ptr& logger){
                if(hasLogger(logger->name())) {
                    return;
                }
                std::unique_lock<std::mutex> lock(_mutex);
                _loggers.insert(std::make_pair(logger->name(), logger));
            }
            bool hasLogger(const std::string& name){
                auto it = _loggers.find(name);
                if(it == _loggers.end())
                    return false;
                return true;
            }
            Logger::ptr getLogger(const std::string& name){
                std::unique_lock<std::mutex> lock(_mutex);
                auto it = _loggers.find(name);
                if(it == _loggers.end()) 
                    return Logger::ptr();
                return it->second;
            }
            Logger::ptr rootLogger(){
                return _root_logger;
            }
        private:
            LoggerManager(){
                std::unique_ptr<log::LocalLoggerBuilder> bulider(new log::LocalLoggerBuilder());
                bulider->buildLoggerName("root");
                _root_logger = bulider->build();
                _loggers.insert(std::make_pair("root", _root_logger));
            }
            //拷贝构造和赋值重载私有化
            LoggerManager(const LoggerManager& ) = delete;
            LoggerManager& operator=(LoggerManager&& ) = delete;
        private:
            std::mutex _mutex;
            Logger::ptr _root_logger;//默认日志器
            std::unordered_map<std::string, Logger::ptr> _loggers;
    };
    //全局日志器的建造者，将日志器添加到单例对象中
    class GlobalLoggerBuilder : public LoggerBuilder{
        public:
            Logger::ptr build() override{
                assert(!_logger_name.empty());//日志器名字是必须要有的
                if(_formatter.get() == nullptr){
                    _formatter = std::make_shared<Formatter>();
                }
                if(_sinks.empty()){
                    buildSink<StdoutSink>();
                }
                Logger::ptr logger;
                if(_logger_type == LoggerType::LOGGER_ASYNC){
                    logger = std::make_shared<AsyncLogger>(_logger_name, _limit_level, _formatter, _sinks, _lopper_type);
                }else{
                    logger = std::make_shared<SyncLogger>(_logger_name, _limit_level, _formatter, _sinks);
                }
                LoggerManager::getInstance().addLogger(logger);
                return logger;
            }
    };
}


#endif

